Having been obvious at its launch the Williams FW33 has a radical shrunken gearbox case. Now we can see how the case is actually configured, which is close to the diagram I posted back in February (http://scarbsf1.wordpress.com/2011/02/10/williams-fw33-lowline-gearbox/). As I explained Williams sought to remove as much blockage ahead of the beam wing as possible, to do this they lowered the top of the gearbox, switched to a Pull-Rod set up and repositioned the differential much lower. The revised layout has lead to a very neat gearcase.
To get a reference point for what we see in this picture, it’s the lower wishbone that’s fitted. This is usually mounted halfway down the gearcase and the top wishbone mounts above it. So what we are seeing is the casing dropping downwards from its front face to create a low flat top. It’s this front face that also gives an idea of how high a conventional gearcase is. So clearly Williams have lowered the case dramatically (see below).
Equally the differential (the diff’ circled above) is very low too, normally its several centimeters above the lower wishbone, now the diff’ is below the wishbone. This is why when we see the car from behind; we can see the driveshaft’s angle upwards from the gearbox at an extreme angle. Above the diff’ is the bolt on wing mount, as explained in my previous article, this metal structure supports both the rear wing and the top wishbone. One curiosity of the diff’ and wing mount set up is how the diff’ is removed. Normally the gearcase is split to allow the differential to be removed from the back of the case. Perhaps with the new Williams set up, the case has a cover over the left hand side of the differential and the diff’ is removed sideways. This set up would create a slightly stiffer case, critical for its complex waisted shape.
Not seen in this picture is the top wishbone, it mounts to the top of the bolt-on metal pylon and also to the pick up on the front of the casing (circled above)
Williams have also switched to a pullrod suspension, this places the rocker linkage and the dampers low down at the front of the gearbox. The dampers heave spring and inerter have to pass horizontally across the front of the gearbox; they enter the gear case via the aperture seen at its lower front side.
More info on Pull Rod Suspension